This is a fascinating story that came up as a side-quest in my copyright investigations around 1965, by Zvi Rosen:

The idea of chance in making music is nothing new, the dice game attributed to Mozart is only one of many examples through history. In the early 1950s the composer John Cage pushed this much farther into what would come to be called aleatory music, using randomness system of the I Ching to compose such works dictated by chance as Imaginary Landscape No. 4 for 12 radio receivers, and Music of Changes for piano. In 1952 this led to his best-known and most controversial creation: 4′33″. The “silent piece,” contains no musical notation beyond three movements and an instruction to [be] silent […]

Cage’s publisher Henmar Press applied to register many of them – including 4’33” – with the U.S. Copyright Office, and in looking at how the applications were handled … there’s some valuable lessons to learn about registration of works of indeterminate authorship. Most notably, although a decent number of Cage’s compositions passed muster and were registered as music, others including 4’33” did not, and after years of considering the issue, were registered instead as textual works by the U.S. Copyright Office.

This seems pretty similar to the Sol Lewitt pieces which consist merely of instructions to create a given work, which is then executed by third parties. More to explore down this particular rabbit hole!